Field of the Disclosure
The present invention relates to methods and apparatuses to make signal path connections between adjacent oilfield devices. More particularly, the present invention relates to methods and apparatuses to make wetmateable signal path connections between adjacent devices in a subsea wellhead stack. More particularly still, the present invention relates to methods and apparatuses to make wetmateable signal path connections between adjacent subsea wellhead stack devices such that the signal path connections may be engaged and/or disengaged without requiring the separation, decoupling, or disengagement between the adjacent subsea devices.
Description of the Related Art
Subsea wellhead assemblies are often used when drilling subterranean formations lying beneath increasingly large depths of ocean water. Because of the challenges associated with performing complex mechanical, electrical, chemical, and hydraulic operations on sea floors beneath hundreds or thousands of meters of sea depth, various connection mechanisms and remotely operated vehicles (ROVs) are used to perform operations where humans cannot directly be present. Following drilling operations, the subsea wellhead must be re-configured from a drilling configuration, to a completion and/or production configuration, whereby conditions and fluids of the subterranean reservoir may be tested, evaluated, and/or produced to the surface for recovery, storage, and transport to a terminal location.
Referring briefly to FIG. 1, a typical subsea completion system 28 comprising a number of devices, such as a wellhead 34, a tubing hanger 38, a tree 30, and blowout preventer (BOP) stack 36 are shown. Such systems (e.g., completion system 28) may also comprise a number of tools which are used temporarily during installation and testing of completion system 28. These tools may include a lower riser package (“LRP”), an emergency disconnect package (“EDP”), and a tubing hanger running tool (“THRT”). During installation, testing, and production, these components and tools are stacked atop and connected to each other in a desired configuration. During the assembly, testing, and production phases of most common subsea systems, the various components are stacked in a particular order, such that a lower connector or flange of each device engages a corresponding upper hub or flange portion of the next device in the “stack” of subsea wellhead devices.
Historically, wetmateable connections between subsea wellhead stack devices (e.g., valve bodies, vertical trees, blowout preventers, tubing hangers, wellhead couplers, etc.) have been “made up” or “broken out” at the time such components are landed, bolted, or otherwise coupled together. Typically, an upper subsea wellhead device includes a plurality of feed-through signal path connection devices extending from a distal end of the device, while the device to be mated to below comprises a plurality of corresponding connection devices upon its proximal end. Thus, the aforementioned signal path connections are made concurrently with the subsea wellhead devices themselves. However, under this arrangement, the only way to break out the signal path connection is to physically separate the adjacent subsea wellhead devices, requiring significant effort and the assistance of subsea ROVs and/or lifting cranes, etc. While there historically has been little need to disconnect the signal path feed-through connections independent of the subsea wellhead devices they connect, there may be advantages to constructing subsea wellhead devices capable of having their signal pathways disconnect independent of the devices themselves.
As used herein, the term, “wetmateable” is defined to include, but not be limited to, any signal pathway or conduit connection in which two environment-immune components are mated together to form either a pressure containing and/or controlling conduit (mechanical, hydraulic, electrical, fiber optical, or otherwise) pathway across the two components. Typically, wetmateable connections are used in environments (such as subsea drilling) where isolating a surrounding or “wet” fluid environment from the proximity of the connection components would otherwise be difficult or extremely costly. For example, a signal pathway connection between a vertical tree and a tubing hanger atop a subsea wellhead could employ a wetmateable connection such that upon engagement of the two components of the signal path, any fluid (e.g. seawater or ambient air) surrounding the connector immediately prior to forming the connection is prevented from interfering with the made-up hydraulic connection. Thus, hydraulic wetmateable connections would prevent surrounding water or air from interfering with the hydraulic fluid of a hydraulic signal path. Similarly, fiber-optic, mechanical, or electrical, wetmateable connections would prevent a surrounding fluid from interfering with the connection or performance of their corresponding optical, mechanical, or electrical signal pathways passing through adjacent subsea wellhead designs.